Sending data from nodemcu v3 to arduino uno

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1

I can't manage to send data from the nodemcu to the arduino uno, I've succeed to send data from the arduino uno to the nodemcu through serial but I just can't send data from the nodemcu to the arduino, through serial of course,

If anyone can help, it will be amazing,
Thanks in advance

schematic
NODEMCU ARDUINO
Tx Rx
Rx Tx

2

Post the sender and receiver codes. I am not familiar with NodeMCU, but i am familiar with ESP8266. Are the NodeMCU inputs 5V tolerant? What NodeMCU pins are you using for RX and TX?